Presidential elections were held in Nigeria on 12 June 1993. The elections were the first held since the 1983 military coup d'état which ended the Second Nigerian Republic. They were the culmination of a transition from military to civilian rule spearheaded by incumbent president Ibrahim Babangida. However, the results were annulled by the military government, citing electoral irregularities, when unofficial returns indicated a substantial victory for Moshood Abiola of the Social Democratic Party over his opponent, Bashir Tofa of the National Republican Convention.
The annulment led to protests and Babangida's resignation as president, the installation of a weak interim civilian government, and the continuation of military rule under Sani Abacha following a bloodless palace coup in November 1993. Abiola, the apparent winner of the election, died in prison in 1998 after he was charged and convicted of treason for declaring himself president and commander-in-chief.
In 1983, the Nigerian army ousted elected president Shehu Shagari following a dispute over Shagari's orders in the Chadian–Nigerian War. Led by Ibrahim Babangida and financed by Egba aristocrat Moshood Abiola, the military installed major general Muhammadu Buhari, the leading commander in Chad, as president of the new military government.
On 27 August 1985, Babangida deposed Buhari through a palace coup. Babangida established the Armed Forces Ruling Council as the formal military government and initiated a transition process to establish the return of civilian rule, targeting October 1990. In 1987, the government established the National Electoral Commission (NEC) to oversee the electoral process. The Babangida government also established the Nigerian Political Bureau of 1986 to advise on this transition. The Bureau's 1987 report recommended the facilitation of political competition to bridge ethnic and religious divides in the country. As a result, Babangida delayed the target for civilian rule to 1992. It was later delayed again to January 1993 before finally being set for 27 August 1993.
To further facilitate political culture, the government created new state and local governments, with the number of states rising from 21 to 30 from 1987 to 1991. Local governments also increased, doubling to almost 600 by 1993. Local government elections were held in 1987 and 1991, and state government elections for the legislature and executive offices were held in 1991 and 1992.
The Babangida government also restricted participation in the new government. Through Decree 25 of 1987, Babangida banned politicians and public officials of the Second Republic from participating in political activities of the Third Republic. During this period, the government also foiled coup attempts by major general Mamman Vatsa in 1985 and major Gideon Orkar in 1990. In late 1992, during the nomination process for the upcoming presidential election, Babangida replaced the Armed Forces Ruling Council with a new National Defense and Security Council and a civilian Transitional Council, led by Ernest Shonekan, a prominent Egba businessman, as head of government.
In May 1989, President Babangida lifted the ban on political parties. Several parties submitted applications for recognition, but only six were approved by the National Electoral Commission, which was handicapped by poor organizational structures and finances and claimed to be unable to verify most of the applicants' claims. In October 1989, however, Babangida rejected these six parties as well, accusing them of being ethnically and regionally polarized and riddled with factions. Instead, Babangida organized two new big tent parties: the right-leaning National Republican Convention (NRC) and the left-leaning Social Democratic Party (SDP), with the government providing initial funding and office space for each. The government was also heavily involved in the formulation of party manifestos and constitutions and trained the parties on electoral techniques through the Centre for Democratic Studies. Overall, the military government spent billions of naira on the transition through the NEC and the parties.
Party primaries for were held in August and September 1992 to nominate presidential candidates, but these were cancelled by Babangida, citing electoral fraud. The candidates who participated in these primaries, including lieutenant general Shehu Musa Yar'Adua and Adamu Ciroma, were barred from contesting again. Instead, a nomination process was established consisting of a "knockout" contest from the local to the national level, using an open ballot system referred to as "Option A4." This nomination process resulted in the nomination of Moshood Abiola, a multimillionaire southern businessman, by the SDP and Bashir Tofa, a northern businessman, by the NRC. Both nominees were Muslim, considered to have close ties to the military, and had been members of the ruling National Party of Nigeria (NPN) during the Second Republic. Although Abiola was widely known throughout the country, having been a candidate for the NPN nomination in the 1983 presidential election against incumbent president Shagari, Tofa was relatively unknown outside of his home state of Kano. Abiola had only been a member of the SDP for a month when he won the nomination.
As a running mate, Tofa selected Sylvester Ugoh, a Christian economist from the south-east, thereby creating a regional and religious balance. Abiola selected former diplomat and former party chairman Baba Gana Kingibe.
Abiola's campaign focused on economic issues. He was a vocal critic of the Banangida government's structural adjustment program, which imposed austerity measures to ensure state fiscal discipline following the prescriptions of the International Monetary Fund and World Bank. Tofa was less vocally critical of the program, given his party platform's support for it, and Babangida, having once suggested that he should remain president until the year 2000. He instead focused on presenting himself as the more effective candidate. Ahead of election day, there were suggestions that the military leadership were uneasy about a possible Abiola presidency and would not accept the result if he won.
On 10 June, just two days before the scheduled election, Arthur Nzeribe and the Association for a Better Nigeria, an organization with ties to the military, obtained a high court injunction against the election on the basis of alleged corruption. Humphrey Nwosu, chair of the NEC, disregarded the injunction and challenged the court's jurisdiction on electoral matters, proceeding with the election as scheduled.
On 13 June, the election was staged in the presence of independent observers, including foreign and local journalists, Commonwealth and other international delegates, and observers trained by the Centre for Democratic Studies. These observers deemed the election free and fair; although there were administrative and political issues, no episodes of serious violence were recorded.
The NEC began announcing the first batch of election results on 14 June: Turnout was low at around 35 percent. Of the 6.6 million votes initially announced, Abiola received 4.3 million. In the initial results, Abiola won 19 out of 30 states, including all states in the southeast and Tofa's home state of Kano, and the Federal Capital Territory, breaking through ethno-religious divides having received support from all regions of the country. Had Abiola been declared the winner, he would have been at that time the first southerner elected as president.
On 15 June, the Association for a Better Nigeria obtained another court injunction to halt the counting and verification of votes. On 16 June, the NEC announced via Radio Nigeria that it would accepted the court injunction and stop the count. However, democracy activists leaked the final unofficial vote on 18 June, defying the law to reveal that Abiola won a 58 percent majority. On 24 June, Babangida announced the annulment of the election, citing claims of vote buying and the need to protect the judiciary.